Several areas of drug abuse related research are being explored, including: 1. Identification of two serotonin receptors and their regulation by guanine nucleotides and drugs. 2. A new technique to visualize by autoradiography in vitro opiate receptors. 3. Mapping of enkephalin and neurotensin neuronal systems. 4. Electrophysiologic studies of enkephalin and neurotensin influences on neuronal firing. 5. Autoradiographic localization of dopamine receptors. 6. Localization of opiate receptors by selective brain lesions. 7. Use of mitotic inhibitors such as methylazoxymethanol, to selectively lesion neuronal populations containing opiate receptors and enkephalin. 8. Purification of benzodiazepine receptors. 9. Separation and isolation of enkephalinases.